Swans are seen at a swan habitat conservation area in the Ili River valley in Yining County, northwest China's Xinjiang Uygur Autonomous Region, Nov. 7, 2011. As more and more swans spend winters in the conservation area in recent years, local government has adopted mesures to protect them. (Xinhua/Lai Yuning)

A pavilion is seen covered with snow in Urumqi, capital of northwest China's Xinjiang Uygur Autonomous Region, Oct. 30, 2011. The city saw its first snow of this winter here on Sunday. (Xinhua/Wang Fei)

Boys of Uygur ethnic group compete in a game in Zepu County, northwest China's Xinjiang Uygur Autonomous Region, Oct. 18, 2011. Zepu County in Xinjiang Uygur Autonomous Region is an area mostly inhabited by people of Uygur ethnic group. The natural sceneries, traditional customs and and life styles there all deliver a strong sense of the Uygur culture. (Xinhua/Wang Song)

The Silk Road is an extensive interconnected network of trade routes across the Asian continent connecting East, South, and Western Asia with the Mediterranean world, as well as North and Northeast Africa and Europe.